Leveling mechanism for headlight testers



June 3, 1952 H, G, HOLMES 2,598,794

LEVEL'NG MECHANISM FOR HEADLIGHT TESTERS Filed April 22. 1946 4 Sheeelzs-Sheeil l FIE `L gmc/wm 2 HERBERT GLENN HOLMES.

June 3,v 1952 H. G. HOLMES y 2,598,794

LEVELING MECHANISM FOR HEADLIGHT TESTERS Filed April 22. 1946 4 sheets-sheet 2 HERBERT GLENN HOLMES.

@MW @WMM @www June 3, 1952 H.v G. HOLMES 2,598,794

LEVELING MECHANISM FOR HEADLIGHT TESTERS.

Filed April 22, 1946 4 Sheets-Sheet 5 F'IE'| :El

wuQ/Yvkyb HERBERT GLENN HOLMES.

@www

June 3, 1952 H. G. HOLMES 2,598,794

LEVEL-ING MECHANISM FOR HEADLIGHT TESTERS Filed April 22, 1946 4 Sheets-Sheet 4 F 'IE Ei FIE HERBERT GLENN HOLMES.

www

Patented June 3, 1952 LVLING MECHANISM FOR HEADLIGHT TESTERSy Herbert Glenn Holmes, Lansing, Mich., assigner to Food Machinery and Chemical Corporation, San Jose, Calif., a corporation of Delaware Original application June 18, 1940, Serial No. 341,178. Divided and this application April 22, 1946, Serial No. 663,909

Claims. l

This invention relates to leveling mechanism for apparatus used for testing the angle of inclination of the light beam projected by an automobile headlight.

This application is a division of my co-pendingapplication Serial No. 341,178, led June 18, 1940, fora Headlight Tester which issued December 3, 1946, as Patent No. 2,411,879.

One object of the present invention is to provide improved leveling mechanism for determining the angle of inclination of the axis of a headlight testing instrument when the axis is aligned with the headlight beam.

Another object is to provide a simple manually adjustable leveling mechanism for use with headlight testing instruments to determine the vertical inclination of the headlight beam.

Another object is to provide mechanism for adjusting the spirit level of the leveling mechanism of a headlight testing instrument to correct the zero position of the level When the automobile is not standing on a true horizontal surface at the time the headlights are being tested.

A further object is to provide mechanism for adjusting the level of headlight testing instruments, which is simple in construction and accurate in operation.

Other and further objects and advantages of the invention will become more apparent from the following description, taken in connection with the accompanying drawings, in Which:

- Fig. 1 is a plan View of a headlight testing instrument provided with the leveling mechanism of the present invention.

Fig. 2 is a vertical longitudinal section taken along line 2-2 of Fig. 1.

Fig. 3 is a horizontal section through the instrument, showing the level adjusting mechanism.

Fig. 4 is a fragmentary vertical section taken along line 4-4 of Fig. 2.

Fig. 5 is a fragmentary horizontal section taken along line 5--5 of Fig. 2.

Fig. 6 is a fragmentary horizontal section taken along line '6 6 of Fig. 4.

In order to facilitate an understanding of the invention, a preliminary explanation will be given in which the general arrangement and use of the headlight testing instrument will be briefly set forth.

The headlight testing instrument comprises a case II (Fig. 1), provided with a handle I2 mounted on the left side I3 and a handle I4 mounted on the right side I5 thereof. When used as a portable instrument the operator holds the instrument in his hands by means of the handles I2, I4 and places the same in the beam of the headlight to be tested by pressing the contact I6, which is preferably made of rubber, against the lens of the headlight.

Rays from the beam of the headlight are admitted to the interior of the instrument through a plurality of orifices I'I (Fig. 3) located about the contact IIi in the front wall I8 of the case II.

The intensity of the light admitted to the instrument from the beam is registered Yon a meter I9 (Fig. l) which is provided with a pointer 20 that moves over a scale 2I calibrated in candle power.

Holding the contact IB against the lens of the headlight the operator manipulates the instrument with a universal movement, that is, left and right, and up and down, until he nds the position of the instrument at which the maximum reading is obtained on the intensity meter I9. The longitudinal axis of the instrument which passes through the center of the contact IB is then substantially in coincidence with the axis of the beam and in parallelism with the rays thereof. In order to determine the direction of the beam, the operator turns the knobl 23 with his left thumb to measure the vertical inclination, and he turns the knob 24 with his right thumb to measure the horizontal inclination. When the knob 23 has been properly ad- `justed, as will presently be described, the operator reads the vertical inclination by means of the pointer 25 on scale 26, and when the knob 24 has been properly adjusted, he reads the horizontal inclination by means of the pointer 2l, which has two cross hairs 28 that cooperate with two sets of scales, one for the right hand lamp, the other for the left hand lamp. These scales are marked on an arcuate strip 29 which is attached by means of screws 30 to the top of the case II. The upper scales 3| are calibrated in inches at twenty-five feet distance and the lower scales are calibrated in degrees, so that the horizontal inclination may be measured either in angular degrees or in inches.

Rigidly mounted within the case II and acurately positioned normal to the axis 33 is a diaphragm 34. The diaphragm 34 (Fig. 3) has a series of apertures 35 which are located in longitudinal alignment with the apertures Il (Fig. 3), and are smaller than the apertures II.

A transparent glass plate 36 is mounted on the front of the diaphragm 34 and covers the `apertures therein. A second diaphragm 31 is rigidly mounted in the rear end of the case II so as to be accurately positioned normal to the longitudinal axis 33. The diaphragm 31 (Fig. 3) has a series of apertures 38 which are the same size as the apertures in the front diaphragm i and are located'in longitudinal alignment therewith. The purpose lof the aligned apertures in the two diaphragms 34 and 31 is to select parallel rays from the beam of the headlight.

When the instrument axis 33 is positioned substantially coincident with the axis of the headlight beam and parallel to the rays thereof, parallel rays such as 33 and 4i) (Fig. 3) will enterv the apertures I1 in the front wall VI8 of the case, pass through the apertures 35 in the front diaphragm 34 and then pass through the apertures 33 in the rear diaphragm 31. It will be apparent that this only occurs when the instrument is positioned so that its axis 33 is parallel to the rays 39, 40, because if the instrument axis 33 is out of parallelism with the rays of the beam,

other rays, although they might enter the apertures I1, would not pass through the aperturesr 38..

A series of planar mirrors 4I (Fig. 3) is mounted on'the rear-side of the rear diaphragm 31 with the mirrors behind, the apertures 38, and so positioned that they will reect the rays into a lightsensitive cell 42, as indicated by lines 43, 54 which converge at V45. This may be called the hot spot of the beam or point of greatest intensity which coincides with the major axis of the beam.

A shield having an aperture 41 is placed over the window of the light-sensitive cell d2.- The shield 46 serves to exclude from the light-sensitive cell all rays reflected thereon except rays such as 33 and 43 which enter the instrument parallel'to its axis 33. It will be noted that the focal point 45 Vof the reected rays lies on the instrument axis Y33, so that rays from Ythe beam,

such as 39 and 4i), are not reflected onto the light-sensitive cell 42 until the instrument axisv 33 is brought into parallelism with the rays ci the beam.

The light-sensitive cell 42 is rigidly mounted on the front diaphragm 34 by means of two bosses 48, 49 (Fig. 3) into which screws 38, 5I are threaded. The light-sensitive cell 42 is of the blocking-layer type, the metallic elements of which create an electromotive force when exposed to light. rlhe electrical response Vof the cell is,V measured by aV sensitive meter I9, elecl:

trically connected to the cell 42 in the mannerv fully described in my co-pending application Serial No. 341,178, which application resulted in the issuance'of Patent No. 2,411,879 dated Detion of the beam is, in this way, determined.

The mechanism by which the vertical angle of inclination of the beam to the line of travel of the vehicle is measured will now be described.

, Thevertical inclination is determined by means Yof a gravity-responsive leveling device which is adjusted by means of the knob 23 (Fig. 1) disposed within the handle` I2'.r 'I'he knob V23 is Secured by means of a set screw 52 to the outer endV of a shaft 53 (Fig. 3) which is mounted for rotation in a boss 54 formed on the side wall I3 of the case. A pinion 55 is secured on the shaft 53 for rotation by the knob 23. A rack 56 (Fig. 2) meshes with the pinion 55. A guide plate 51 is rigidly Vattached to the rack 56 and has a slot 53 therein through which-the shaft 53 passes so that the rack 55 is guided for sliding movement with respect to the shaft 53 and is maintained in mesh with the pinion 55. The forward end of the rack 55 is pivotally connected at 53 to the pointer 25. The foot of the pointer 25 is pivotally supported at (i9 on a bar 6I which is provided with two slots 52, 63 to receive screws 64, 65 which are threaded into bosses 63,Y 61 (Fig. 3) formed on the side' wall I3 of the case. By loosening the screws 64, 65 the bar 8| may be moved forwardly or rearwardly to position the pivotal center 33 of the pointer 25. This adjustment is usually made at the factory for a purpose presently to be described. A lever 68 (Fig. 2) is connected by pin and slot connection 69 to the pointer 25. The lever 58 is rotatably mounted by means of a pin 15 (Figs. 2 and 5) secured thereto and having bearing in an aperture 1I in a member 12 which is rigdly'mounted on the side wall I3 by means of screws 13, 14 which extend through spacing sleeves 15, 16. It will be understood that the member 12 is fixed, but the pin 18 is free to rotate inthe aperture 1I, thus providing a fulcrum for the lever 88. The upper end of the lever 58 (Figs. 2 and 4) has a spirit level 11 rigidly secured thereto.

By means of the linkage construction just described, the rack 55 (Fig. 2) oscillates the pointer and through pin ancl'slot connection 89 the lever 5S is free to pivot at 1! thereby rocking the spirit level 11 responsive to the movement of the pointer 25. The construction of the linkage is such that while the movement of the pointer is proportional to the movement of the spirit level, the movement of the pointer is greatly multiplied to facilitate obtaining a reading on the scale 26. Also, the movements are in opposite directions; that is, when the rack 56 moves the pointer25 to the left in Fig. 2, the level 11 is rocked to the right. further facilitates making the adjustment in that the pointer moves in the same direction as the bubble 13 of the level The scale 25 (Fig. 2) is arcuate in shape and is secured at its outer edge 19 (Fig. 4) to a vertical plate 38 having slots 3 I, 82 (Fig. 5) through which the spacing sleeves 15, 15 extend. Springs 83, 84 coiled about the sleeves 15, 1S bear against washers 85, 85 to apply friction to the plate 8G to hold the plate 88 in its adjusted position on the sleeves 15, 1S. It will be understood that the plate 38 vis supported by means of these sleeves but is slidably adjustable thereon by reason of the slots 8l, 32. In order to impart sliding adjustment to the scale plate (Fig. 6) a knob 81 is provided outside the side wall I3. A screw 88, which is slidable in a slot 89 (Fig. 6), formed in the wall I3 is threaded into the knob 31. The screw 88 passes through a member 98 which has pins SI, 92 engaging in apertures 93, 94 in the scale plate 38. In order to adjust the scale 2S the operator unscrews the knob 81 from the screw 38 a sufficient amountV to permit movement of the knob back and forth, thus causing the scale Vplate 8l) to slide on the sleeves 15, 15. When the scale 23 has been positioned as desired, the knob 81 is tightened to hold true horizontal surface at the time the headlights are being tested.

The operator makes the corrective adjustment by placing the instrument on a part of the car which is known to be level, such as the running board or the Iioor of the trunk compartment, and leveling the spirit level 11 (Fig. l) by turning the knob 23. When the bubble 18 is between the centeringlines 95, 96, which are marked onthe glass tube of the level, the pointer 25 is opposite the mark 91 at the center of the bubble if the surface on which the automobile is standing is horizontal. However, if the surface is inclined to the horizontal, the pointer 25 will not be opposite the mark 91 at the center of the bubble when the bubble is centered between the lines 95, 96. The operator is ableto correct for this condition by loosening the knob 81 and shifting the scale 26 until the zero point is opposite the pointer A25. He then locks the scale in this corrected position by screwing the knob 81.

After this preliminary adjustment the operator places the instrument in front of one of the headlights, holding it by the handles I2, I4, and presses the contact I6 against the center of the lens. Maintaining sufficient Ipressure on the rubber contact I6 to prevent the contact from slipping on the lens, he manipulates the instrument, employing the flexible contact I6 as a universal pivot, until he finds the position of the instrument at which a maximum reading is obtained on the meter scale 2|. When the meter indicates that the instrument axis has thus been brought into line with the headlight beam, the operator holds the instrument stationary and turns the knob 23 with his thumb, so as to return the bubble 18 to its central position between the centering lines 95, 96. After this has been done the position of the pointer 25 on the scale 26 is read, and this reading is an indication of the vertical inclination of the beam to' the line of travel of the automobile.

As previously mentioned, the adjustment of the pointer 25 (Fig. 1) is facilitated by the fact that the pointer moves in the same direction as the bubble 18 so that, for example, when the instrument has been positioned to obtain the maximum reading on the meter I9, if the bubble 18 is rearward of the centering line 96, the operator turns the knob 23 to move the pointer 25 forwardly, and in so doing moves the bubble forwardly. As can be seen in Fig. 2, when the pointer 25 is rocked forwardly, that is, to the right in this view, the lever 68 is turned counterclockwise on its pivot 10, thus causing the bubble 18 to move to the right or forwardly in the same direction as the pointer 25. Due to this linkage construction, there is only one position of the pointer 25 and lever 68 in which the pointer is opposite the bubble 18. This is the true horizontal position, that is, when the axis of the instrument is horizontal. The pointer is adjusted to this position at the factory by loosening the screws 64, 65 and sliding the bar 6I forwardly or rearwardly when the instrument is placed on a surface which is known to be horizontal.

While I have described a particular embodiment of the present invention, it will be obvious that various changes and modifications may be made in the details thereof without departing from the spirit of the present invention and the scope of the appended claims.

Having thus described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. A leveling mechanism for a headlight testing instrument having a reference axis adapted to be' aligned with the beam of light projected from a headlight, comprising a scale on said instrument, a pointer pivotally mounted on said instrument for movement over the scale, a spirit level pivotally mounted on said instrument between said scale and the pivotal mounting of said pointer, means pivotally connecting said pointer with said level between their respective pivots, and means for operating said pointer to positionthe level for vcentering the bubble thereof horizontally in the levelk whereby the pointer indicates on the scale the inclination of the headlight beam above or below the horizontal.

2. Leveling mechanism for an instrument having a reference axis adapted to be aligned with the beam projected by a headlight, comprising a scale on said instrument, a pointer arm pivoted on said 'instrument for movement over said scale,'a lever connected by a pin and slot arrangement to'said pointer intermediate the pivot thereof and said scale, a fulcrum for said lever,

`a spirit level mounted on said lever for movement simultaneously with said pointer, and manually operable means for operating said lever to center the bubble of said level when the reference axis of said instrument is inclined to the horizontal and to position the pointer to indicate on the scale the elevation of the headlight beam above or below the horizontal.

3. A leveling mechanism for a headlight testing instrument having a reference axis adapted to be aligned with the beam projected from a headlight so as to determine the vertical inclination of the beam projected by the headlight, comprising a scale having a zero indicating mark, an arm pivotally mounted on said instrument and having a pointer movable over the scale, a spirit level disposed adjacent said scale and pivotally mounted adjacent the same for movement relative to the zero mark thereof, and motion-transmitting means interconnecting said arm and said level for opposite rotation on their respective pivots, and means for moving said arm in one direction whereby said pointer will move in the same direction as the bubble of said level to indicate the horizontal position of said level with respect to the zero indicating mark on the scale.

4. Leveling mechanism for a headlight testing instrument having a reference axis adapted to be positioned4 in alignment with the headlight beam to determine the vertical inclination of the beam projected by the headlight, comprising a scale mounted on the instrument and having a zero indicating mark, means for adjusting the scale to dispose its zero indicating mark at a predetermined position, a pointer pivotally mounted on said instrument for movement over the scale, a lever pivotally mounted on said instrument between the scale and the pivot of said pointer, a spirit level disposed on said lever adjacent said scale, and motion-transmitting means interconnecting said pointer and said lever between the pivotal mountings thereof for opposite rotation on their respective pivots, whereby said pointer will move in the same direction as the bubble of said level to facilitate adjusting said level to horizontal position.

5. Leveling mechanism for an instrument having a reference axis adapted to be aligned with the beam projected by a headlight, comprising a scale mounted on the instrument, a pointer 7, pivoted formovement over the scale, a lever connected to said pointer intermediate the pivot thereof and ysaid scale, a fulcrum for `said lever located between the scale and the .connection of said lever With said pointer, a spirit level mounted on said lever and movable therewith When said,Y pointer is moved, a rack bar for operating said Y pointer, a vpinion for operating said rack bar, and manually operable means for actuating the pinion whereby to center the bubble of said level relative to horizontal when the reference axis of said instrument is incli ed with respect to horizontal and to simultaneously position the pointer to indicate on the scale the elevation of the headlight beam above or beloiv horizontal.

6. An automobile headlight testing instrument comprising a case adapted to be placed in a predetermined position with respect to a headlight beam, a scale within the case and visible -:from the `exterior thereof, a pointer pivotally mounted within said case for movement over said scale to indicate the verticalV inclination of the case to thehorizontal, a spirit level Within said case adjacent said scale, a lever carrying'said level at one end and having its opposite end connected to said pointer for pivotal sliding movement relative thereto, a fulcrurn for said lever mounted in the case adjacent said level, and

Y means connected to said pointer for imparting oppositeY movements to said pointer and said level on their respective pivot and fulcrum whereby to move said pointer in the same direction as the bubble ci said level upon adjustment of said level with respect to horizontal position.

7. A leveling mechanism for a headlight testing instrument having a reference axis adapted to be aligned with the light beam projected 'by a headlight to `be tested, comprising a scale on said instrument, a pointer pivoted on said instrument for movement over said scale, a lever having a slotted end pivotally connectedto said pointer adjacent the pivot thereof, a fulcrum for said lever adjacent said scale, a spirit level mounted on said lever aside of 'said scale, and manually operable VmeansY for actuating said pointer relative to said scale and moving the level until the bubble thereof assumes horizontal.

8. In a device for determining the vertical inclination of the beam of light projected from af headlight, Y a leveling mechanism comprising means for orient-ing said device with respect to said light beam, a scale on said device, a pointer pivoted on said device for movement over said scale, aflever connected byY pin and slot connection to said pointer intermediate the pivot thereof and said scale, a spirit level mounted on 8 said lever adjacent said scale, a fulcrum for said lever between said pin and slot connection and said spirit level, and means for actuating said pointer to position the pointer relative to said scale and simultaneously rock said level until the bubble thereof is set at horizontal and said pointer l indicates on said scale the angle of inclination of the headlight beam with respect to horizontal.

9. A leveling mechanism for a headlight tester having a reference axis adapted to be aligned with a light beam projected from av headlight to be tested, comprising a scale mounted on said headlight tester, an arm pivotally mounted on said tester and having a pointed end movable contiguous to said scale, a lever pivotally mounted on said tester between said scale and the pivotal mounting of said arm, a spirit level carried by said lever adjacent said scale for movement relative thereto, means for interconnecting said lever and arm intermediate the respective pivotal mountvings thereof, and manually controlled T eans for rotating said lever and arm inversely with respect to each other.

10. A leveling mechanism Ior a headlight testing instrument having a reference axis, said leveling mechanism comprising a scale on said instrument, a pointer arm pivotally mounted remote from said scale and having a pointer movable lover the scale, a spirit level pivotally mounted on the instrument adjacent said scale, and motiontransmitting means interconnecting said pointer arm and said level between their respective pivots for eiecting opposite rotation of Asaid arm and level about their respective pivots to thereby move said pointer in the same direction as the lbubble of said level to facilitate adjusting said level to horizontal position when the instrument is positioned in the headlight beam with its reference axis aligned with the beam.

HERBERT GLENN HOLMES.

REFERENCES CETEE) The following references'are of record in the le of this patent:

UNITED STATS PATENTS Holmes Dec. 3, 1946 

